Answer:
T = 16
Step-by-step explanation:
As triangles are similar
AB/DE = BC/EF = AC/DF
13.5/18 = 6/4 = 12/T
3/4 = 3/4 = 12/T
3/4 = 12/T
T = 12×4/3
16.1
Find the square root of difference of the squares
the bottom right